Administrator Guide

VTY Line and Access-Class Conguration
Various methods are available to restrict VTY access in the Dell Networking OS. These depend on which authentication scheme you
use — line, local, or remote.
Table 56. VTY Access
Authentication Method VTY access-class support? Username access-class
support?
Remote authorization
support?
Line YES NO NO
Local NO YES NO
TACACS+ YES NO YES (with the Dell Networking
OS version 5.2.1.0 and later)
RADIUS YES NO YES (with the Dell Networking
OS version 6.1.1.0 and later)
The Dell Networking OS provides several ways to congure access classes for VTY lines, including:
• VTY Line Local Authentication and Authorization
• VTY Line Remote Authentication and Authorization
VTY Line Local Authentication and Authorization
Dell Networking OS retrieves the access class from the local database.
To use this feature:
1. Create a username.
2. Enter a password.
3. Assign an access class.
4. Enter a privilege level.
You can assign line authentication on a per-VTY basis; it is a simple password authentication, using an access-class as authorization.
Congure local authentication globally and congure access classes on a per-user basis.
The Dell Networking OS can assign dierent access classes to dierent users by username. Until users attempt to log in, the system
does not know if they will be assigned a VTY line. This means that incoming users always see a login prompt even if you have
excluded them from the VTY line with a deny-all access class. After users identify themselves, the system retrieves the access class
from the local database and applies it. (The Dell Networking OS then can close the connection if a user is denied access.)
NOTE: If a VTY user logs in with RADIUS authentication, the privilege level is applied from the RADIUS server only if you
congure RADIUS authentication.
The following example shows how to allow or deny a Telnet connection to a user. Users see a login prompt even if they cannot log in.
No access class is congured for the VTY line. It defaults from the local database.
NOTE: For more information, refer to Access Control Lists (ACLs).
Example of Conguring VTY Authorization Based on Access Class Retrieved from a Local Database (Per User)
Dell(conf)#user gooduser password abc privilege 10 access-class permitall
Dell(conf)#user baduser password abc privilege 10 access-class denyall
Dell(conf)#
Dell(conf)#aaa authentication login localmethod local
Dell(conf)#
Dell(conf)#line vty 0 9
Security
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